Method and system for joining aluminum roof component to steel vehicle body component

ABSTRACT

A vehicle assembly method includes providing an aluminum roof component including a peripheral flange structure that defines a roof adhesive bonding zone; providing a steel vehicle body component including a body adhesive bonding zone; removably fastening the roof component to the vehicle body component with the peripheral flange structure spaced from the vehicle body component; electrocoating the roof component secured to the vehicle body component including the roof adhesive bonding zone and the body adhesive bonding zone; painting the roof component secured to the vehicle body component; removing the painted roof component from the painted vehicle body component; applying an adhesive that is curable at room temperature to at least one of the roof adhesive bonding zone and the body adhesive bonding zone; securely fastening the painted roof component to the painted vehicle body component with the adhesive spanning the adhesive bonding zones; and curing the adhesive.

BACKGROUND

In the manufacture or assembly of a vehicle body, it is known to have anassembly line including a plurality of stations in which the vehiclebody is assembled and forwarded as the assembly work proceeds.Typically, the major structural components of the vehicle body areformed of low carbon steel or steel-based alloy panels that are weldedtogether in general welders (i.e., stations wherein primary weldingoperations are performed to connect the vehicle body components tocreate the body-in-white body).

The substitution of aluminum or aluminum-based alloy roof components forthe low-carbon steel or steel alloy roof components most commonly usedin motor vehicles is an attractive option for vehicle mass reduction.Often, however, the remainder of the vehicle body component continues tobe fabricated of steel. Joining an aluminum roof component to a steelbody component presents difficulties because the aluminum roof componentcannot be set and joined in the existing general welder due to equipmentand process constraints. Therefore, it is known for manufacturers tosecure the aluminum roof component to the steel body component after theweld process in assembly. This process typically includes an adhesivebonding operation and fasteners can also be used to secure the aluminumroof component to the steel body. This approach, though appealing from avehicle mass-reduction viewpoint, raises issues due to the significantlydifferent coefficients of thermal expansion of aluminum and steel (about22.5×10⁻⁶ m/m K for aluminum and about 13×10⁻⁶ m/m K for steel). Thecombination of the aluminum roof component attached to the steel bodycomponent may create compressive stresses in the aluminum roof componentwhen the body component is subjected to elevated temperatures such asthose required to cure or bake the paint applied to the steel bodycomponent and to cure the adhesive bonding the aluminum roof componentto the steel body. These stresses may lead to unacceptable appearancefeatures in the visible segment of the aluminum roof component, and ifleft unconstrained, the aluminum roof component would bow enough tobreak the adhesive bond between the aluminum roof component and thesteel vehicle body.

One manner of ensuring proper adhesion of the aluminum roof component tothe steel body component is to apply the adhesive after completing theelectrocoating bath and painting processes. The aluminum roof componentis positioned above the steel body component using temporary stand-offfixtures. The spacing created by these stand-off fixtures allows fore-coat and paint coverage. Because the stand-off fixtures do notstrongly affix the aluminum roof component to the steel body component,deformation of the aluminum roof component in the ovens is avoided. Thealuminum roof component is then removed from the stand-off fixtures, thestand-off fixtures are removed, the adhesive is applied to the aluminumroof component, and the aluminum roof component is positioned on thesteel body component in the final installation configuration. Althoughthis manufacturing process can prevent the deformation of the aluminumroof component, assembly time is increased as the stand-off fixturesmust first be installed and removed. In addition, because the aluminumroof component is positioned much farther apart from the steel body, theflange of steel body component where the adhesive is applied is exposedto paint and may not provide a good bonding surface unless the flange ismasked. However, applying and removing masking to the adhesive bondingsurfaces further increases the assembly time and cost.

BRIEF DESCRIPTION

According to one aspect, a method of securing a roof component formed ofaluminum or aluminum-based alloy to a vehicle body component formed of asteel or steel-based alloy comprises providing a roof componentincluding a peripheral flange structure that defines a roof adhesivebonding zone; providing a vehicle body component, the vehicle bodycomponent includes a body adhesive bonding zone; removably fastening theroof component to the vehicle body component with the peripheral flangestructure spaced from the vehicle body component; electrocoating theroof component secured to the vehicle body component including the roofadhesive bonding zone and the body adhesive bonding zone; painting theroof component secured to the vehicle body component; removing thepainted roof component from the painted vehicle body component; applyingan adhesive that is curable at room temperature to at least one of theroof adhesive bonding zone and the body adhesive bonding zone; securelyfastening the painted roof component to the painted vehicle bodycomponent with the adhesive spanning the adhesive bonding zones; andcuring the adhesive.

According to another aspect, a method of securing a roof componentformed of aluminum or aluminum-based alloy to a vehicle body componentformed of a steel or steel-based alloy comprises providing a roofcomponent that includes a roof adhesive bonding zone; providing avehicle body component that includes a body adhesive bonding zone;positioning the roof adhesive bonding zone opposite the body adhesivebonding zone to define a spacing therebetween having a predetermineddistance; removably fastening the roof component to the vehicle bodycomponent, the fastened connection is inwardly of the roof and bodyadhesive bonding zones; electrocoating the roof component secured to thevehicle body component including the roof adhesive bonding zone and thebody adhesive bonding zone; painting the roof component secured to thevehicle body component without masking the e-coated adhesive bondingzones; removing the painted roof component from the painted vehicle bodycomponent; applying an adhesive to at least one of the roof adhesivebonding zone and the body adhesive bonding zone; securely fastening thepainted roof component to the painted vehicle body component with theadhesive positioned in the spacing to bond the roof adhesive bondingzone to the body adhesive bonding zone; and curing the adhesive.

According to another aspect, a system for assembling a vehicle bodyincludes an assembly line having a plurality of stations. At least onefirst station is adapted to weld first structural components that definea vehicle body component. The vehicle body component has a body adhesivebonding zone which defines an opening on the vehicle body component. Thefirst structural components are formed of a first material. At least onesecond station receives the vehicle body component from the at least onefirst station. The at least one second station is adapted to releasablyfasten second structural components that define a roof component to thevehicle body component. The roof component covers the opening and has aroof adhesive body zone corresponding to the body adhesive boding zone.The second structural components are formed of a second material that isdifferent from the first material. At least one third station downstreamof the at least one second station is adapted to at least one ofelectrocoat and paint the vehicle body component together with the roofcomponent fastened thereto. At least one fourth station receives thevehicle body component together with the roof component fastened theretofrom the at least one third station. The at least one fourth station isadapted to detach the roof component from the vehicle body component,apply a structural adhesive to at least one of the body adhesive bondingzone and the roof adhesive bonding zone that is curable at roomtemperature, and securely fasten the roof component to the vehicle bodycomponent after the application of the adhesive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a system for assembling a vehicle body,including a first assembly line, a second assembly line separate fromthe first assembly line, and a third assembly line separate from thefirst and second assembly lines.

FIG. 2 is a schematic view of the second assembly line, a leftmost bodystation for receiving an assembled vehicle body component of the vehiclebody from the first assembly line.

FIG. 3 is a perspective view of the vehicle body including the vehiclebody component and a vehicle roof component secured thereto.

FIG. 4 is a plan view of the vehicle roof component.

FIG. 5 is a cross sectional view taken along line A-A of FIG. 3.

FIG. 6 is a cross sectional view taken along line B-B of FIG. 3.

FIG. 7 is a cross sectional view taken along line C-C of FIG. 3.

FIG. 8 is a cross sectional view taken along line D-D of FIG. 3.

FIG. 9 is a cross sectional view taken along line E-E of FIG. 3.

FIG. 10 is a cross sectional view taken along line F-F of FIG. 3.

FIGS. 11A-11E are detailed perspective views of mounting locations onthe vehicle body.

FIGS. 12-14 depicted alternative aspects of a rear support bracket forthe vehicle roof component.

DETAILED DESCRIPTION

It should, of course, be understood that the description and drawingsherein are merely illustrative and that various modifications andchanges can be made in the structures disclosed without departing fromthe present disclosure. As used herein, lateral directions aretransverse across the vehicle body, i.e., left and right directions.Likewise, longitudinal directions refer to forward and rearwarddirections of the vehicle body, and the vertical directions relate toelevation, i.e., upward and downward directions.

Referring now to the drawings, wherein like numerals refer to like partsthroughout the several views, FIGS. 1 and 2 schematically illustrate asystem 100 for assembling a vehicle body 102, according to the presentdisclosure. The system 100 can generally include a first assembly line110, a second assembly line 112 separate from the first assembly line110, and a third assembly line 114 separate from each of the first andsecond assembly lines 110, 112. The first assembly line has a pluralityof first stations 120, including welding stations for welding firststructural components that together define a vehicle body component 124of the vehicle body 102. The vehicle body component 124 is formed of afirst material such as a steel or steel-based alloy. The second assemblyline 112 receives the vehicle body component 124 from the first assemblyline. The second assembly line has a plurality of second stations 130,132, 134, 136, and is adapted to secure a second structural component(i.e. a roof component 140) to the vehicle body component 124. Thesecond structural component 140 is formed of a second material, whichcan be an aluminum or aluminum-based alloy. The third assembly line 114is configured to assemble and transfer the roof component 140 to thesecond assembly line 112 for attaching the roof component 140 to thevehicle body component 124.

In contrast to the above described known method of applying a structuraladhesive after the electrocoating (e-coat) and painting processes, inthe second assembly line 112, the vehicle body component 124 is providedwith a limited number of fasteners (e.g., 4-5 bolts) that sufficientlyconstrain the roof component 140 to hold it in place during the e-coatand painting processes (depicted at station 132 which for ease ofdiscussion can be part of the second assembly line 112), but looselyenough to allow the aluminum roof component 140 to expand and contractto avoid damage as the vehicle body 102 is subjected to elevatedtemperatures such as those required to cure or bake the paint applied tothe vehicle body. However, the fasteners are not separate parts that areremoved after the e-coat and painting processes but are part of thefinished assembly. Therefore, when the roof component 140 is temporarilysecured to the vehicle body component 124 with the fasteners at station130, it is secured in the same installation position that the roofcomponent 140 will be in on the finished vehicle body. This providescertain benefits over the known method. For example, it eliminates thestep of removing required spacers or other fixtures. It also maintainsthe spacing between the roof component 140 and vehicle body component124 to allow all of the parts to be e-coated, but close enough toprevent paint spray from contaminating bonding surfaces of theto-be-applied adhesive.

As shown in FIG. 2, the roof component 140 is removably fastened to thevehicle body component 124 at station 130 so that a periphery flangestructure 150 (FIG. 4) of the roof component 140 is spaced from thevehicle body component 124. FIGS. 11A-11E depict fastening locations atstation 130. The assembly is then transferred to the station 132 for thee-coat and painting processes. After the paint is cured or baked, theassembly is then transferred to station 134 where the painted roofcomponent 140 is removed from the painted vehicle body component 124 andan electrically nonconductive adhesive 156 (e.g., a high modulusurethane adhesive curable at room temperature) is applied to at leastone of a roof adhesive bonding zone 160 and body adhesive bonding zone162 (FIGS. 5-10). Because the adhesive 156 is applied after the e-coatand painting processes, the adhesive is adapted to accommodate paintoverspray on the adhesive bonding zones 160, 162. Then at station 136the painted roof component 140 is securely fastened to the paintedvehicle body component 124 with the adhesive 156 spanning the adhesivebonding zones.

The first and second structural components of the respective vehiclebody component 124 and the roof component 140 will now be described ingreater detail. With reference to FIG. 3, the vehicle body component 124can be formed of a pair of laterally spaced body members or side panels170, 172 and a floor panel 176, which together define a passengercompartment 178. The side panels 170, 172 may be identicallyconstructed, but for their disposition on opposite sides of the vehiclebody 102, and each side panel 170, 172 can define a respectivelongitudinal extending side roof rail 180, 182. A front roof rail 186and a rear roof rail 188 span laterally between the side panels 170,172. At least one cross member or roof bow 190 (FIGS. 10 and 11D) can beinterposed between the front and rear roof rails 186, 188 and extendsbetween the side panels 170, 172. The side panels 170, 172 together withthe front and rear roof rails 186, 188 support the roof component 140over the passenger compartment 178.

With reference to FIG. 4, the roof component 140 includes an aluminum oraluminum-based alloy roof panel 200 which overlies the passengercompartment 178. The roof panel 200 is generally rectangular in planview but because individual vehicle roof components are required toconform to vehicle styling, the roof panel 200 can have alternativeshapes. The roof panel 200 includes a forward end portion 202, arearward end portion 204 and opposite side portions 206, 208 whichextend longitudinally between the forward and rearward end portions. Asis well known, an opening 210 can be provided in the roof panel 200 fora sunroof assembly (not shown). The roof component 140 further includesat least one roof stiffener. In the illustrated aspect, the at least oneroof stiffener can include roof stiffeners 220, 222, 224, 226 whichextend laterally across the roof panel 200 between the side portions206, 208. In the assembled condition of the vehicle body 102, the roofstiffener 222 overlies the roof bow 190. Front and rear support brackets230, 232 and side brackets 234, 236 are secured to the roof panel 200.The front and rear support brackets 230, 232 also extend laterallyacross the roof panel 200 between the side portions 206, 208. The sidebrackets 234, 236 extend longitudinally on the roof panel 200 betweenthe front support bracket 230 and the roof stiffener 224. The supportbrackets are depicted as one-piece parts; although, it should beappreciated that alternative configurations are contemplated. Forexample, the side brackets 234, 236 can be two-piece parts with forwardparts of the side brackets integrally formed with the front supportbracket 230 and the roof stiffener 226 rearward of the opening 210 (FIG.11C). This arrangement of the support brackets defines a one-piecerectangular-shaped support bracket which frames the opening 210, and endportions of the roof stiffener 226 can overlie the side brackets 234,236. Each support bracket s separate from the roof panel 200 and isfixedly secured thereto to facilitate attachment of the roof component140 and vehicle body component 124. The roof stiffeners and the supportbrackets of the roof component 140 are formed of an aluminum oraluminum-based alloy.

FIGS. 5, 6, 11A and 11B depict the front roof rail 186 connected to theforward end portion 202 of the roof panel 200 via the front supportbracket 230. The front roof rail 186 includes an outer panel 240 and aninner panel 242 that is fixedly attached (e.g., welded) to the outerpanel. As is well known, a reinforcement (not shown) can be interposedbetween the outer and inner panels. The outer panel 240 defines aforward section 246 of the body adhesive bonding zone 162 which, asindicated above, underlies the roof adhesive bonding zone 160. As shown,the section 246 can be recessed inwardly toward the inner panel 242which provides a predetermined spacing from the peripheral flangestructure 150 of the roof component 140. The forward end portion 202 ofthe roof panel 200 includes a forward section 250 of the flangestructure 150 having a vertical wall 252 and a lower horizontal wall 254(lower relative to an upper surface of the roof panel 200). Thehorizontal wall extends beneath an end portion of a windshield 260adhered or bonded to an outer flange structure 258 of the front roofrail 186. The front support bracket 230 is configured to verticallyspace the forward section 250 of the flange structure 150 of the roofcomponent 140 from the vehicle body component 124, and provide acontinuous vertical spacing between the flange structure 150 of the roofcomponent 140 and the vehicle body component 124 of approximately 4 mmto approximately 6 mm. In the depicted embodiment, the front supportbracket 230 includes a raised portion 262 in abutting relation with alower surface of the roof panel 200 and a support/mounting portion 264to be fastened to the front roof rail 186. Locking members, such as weldnuts or swage nuts 268, are secured to the support portion 264. As showin FIGS. 6 and 11B the weld nut 268 is aligned with an opening 270provided in an inner flange structure 272 of the front roof rail 186. Afastener 274 (e.g., a bolt) inserted through the opening 270 threadinglyengages the weld nut 268. The horizontal wall 254 of forward section 250of the flange structure 150 is aligned with the section 246 of the outerpanel 240 and is adhered or bonded to the horizontal wall 254 via theadhesive 156 during the vehicle body assembly described above. Thispositions the connection between the front support bracket 230 and thefront roof rail 186 inwardly of the adhesive 156.

FIGS. 7 and 11C depict the side roof rail 180 of the side panel 170connected to the side portion 206 of the roof panel 200 via the sidebracket 234. To simplify the explanation of the present disclosure, onlythe construction of the side panel 170 and its connection to the roofcomponent 140 will be discussed, but it should be understood that theside panel 172 can have the same construction with a similar connectionto the roof component 140. The side roof rail 180 includes an outerpanel 280 and an inner panel 282 that is fixedly attached (e.g., welded)to the outer panel. A reinforcement 284 can be interposed between theouter and inner panels. The side roof rail 180 includes a flangestructure 288. In the depicted aspect, the flange structure 288 definesa side section 290 of the body adhesive bonding zone 162 which, asindicated above, underlies the roof adhesive bonding zone 160. Aconnector 294 fixedly attached (e.g., welded) to the inner panel 282includes a raised end section 296 for attachment to the roof component140. The side portion 206 of the roof panel 200 includes a side section300 of the peripheral flange structure 150 having a vertical wall 302and a lower horizontal wall 304 (lower relative to the upper surface ofthe roof panel 200). The horizontal wall 304 overlies the flangestructure 288 of the side roof rail 180.

The side support bracket 234 is configured to vertically space the sidesection 300 of the flange structure 150 of the roof component 140 fromthe vehicle body component 124, and provide a continuous verticalspacing between the flange structure 150 of the roof component 140 andthe vehicle body component 124 of approximately 4 mm to approximately 6mm. In the depicted embodiment, the side bracket 234 includes a mountingsection 310 and an extension section 312 which is vertically offsetrelative to the mounting section. An end portion of the roof stiffener226 overlies the mounting section 310 and includes locking members, suchas weld nuts or swage nuts 316, secured thereto. The end section 296 ofthe connector 294 is fastened to the mounting section 310 and the roofstiffener 226 via fasteners 320 (e.g., bolts) inserted through openingsin the end section 296 and mounting section 310 and threadingly engagingthe weld nuts 316. The extension section 312 extends at least partiallybeneath the horizontal wall 304 of the flange structure 150 and an endthereof is spaced inwardly from an end of the horizontal wall 304. Thehorizontal wall 304 of side section 300 of the flange structure 150 isaligned with the flange structure 288 of the side panel 170 and isadhered or bonded to the horizontal wall 304 via the adhesive 156 duringthe vehicle body assembly described above. This positions the connectionbetween the side bracket 234 and the connector 294 inwardly of theadhesive 156.

FIGS. 8, 9 and 11E depict the rear roof rail 188 connected to therearward end portion 204 of the roof panel 200 via the rear supportbracket 232. The rear roof rail 188 includes an outer panel 330 and aninner panel 332 that is fixedly attached (e.g., welded) to the outerpanel. Again, a reinforcement (not shown) can be interposed between theouter and inner panels. The outer panel 330 defines a rearward section336 of the body adhesive bonding zone 162 which, as indicated above,underlies the roof adhesive bonding zone 160. As shown, the section 336is provided on a landing 340 of a step portion 342 on the outer panel330. The rearward end portion 204 of the roof panel 200 includes arearward section 350 of the peripheral flange structure 150 having avertical wall 352 and a lower horizontal wall 354 (lower relative to theupper surface of the roof panel 200). The rear support bracket 232 isconfigured to vertically space the rearward section 350 of the flangestructure 150 of the roof component 140 from the vehicle body component124, and provide a continuous vertical spacing between the flangestructure 150 of the roof component 140 and the vehicle body component124 of approximately 4 mm to approximately 6 mm. In the depictedembodiment, the rear support bracket 232 includes a raised portion 360in abutting relation with the lower surface of the roof panel 200 and asupport/mounting portion 362 to be fastened to the rear roof rail 188. Alocking member, such as a self-clinching threaded stud 368, is securedto the support portion 264 and is aligned with an opening provided inthe outer panel 330 of the rear roof rail 188. A nut 370 threadinglyengages the stud 368. The horizontal wall 354 of rearward section 350 ofthe flange structure 150 is aligned with the landing 340 of the outerpanel 330 and is adhered or bonded to the horizontal wall 354 via theadhesive 156 during the vehicle body assembly described above. Thispositions the connection between the rear support bracket 232 and therear roof rail 188 inwardly of the adhesive 156.

According to an aspect of the rear support bracket 232 depicted in FIG.8, a rearward end portion 374 is curved downwardly and spaced from thevertical wall 352 of the rearward section 350. According to an aspect ofthe rear support bracket 232 depicted in FIG. 12, the rearward endportion 374 is curved downwardly and is fixedly attached (e.g., welded)to the vertical wall 352. According to an aspect of the rear supportbracket 232 depicted in FIG. 13, the rearward end portion 374 is shapedto conform to rearward section 350 and is fixedly attached (e.g.,welded) thereto. The rearward end portion 374 underlies and abuts thehorizontal wall 354 and is bonded or adhered to the outer panel 330 viathe adhesive 156. Therefore, according to this embodiment, the rearwardend portion 374 at least partially defines the roof adhesive bondingzone 160. According to an aspect of the rear support bracket 232depicted in FIG. 14, the rearward end portion 374 is shaped to conformto rearward section 350 and is fixedly attached (e.g., welded) thereto.The rearward end portion 374 underlies and abuts the horizontal wall 354and is spaced inwardly from the adhesive 156. FIGS. 12-14 further depicta rear gutter 380 defined by the rear roof rail 188 and a tail gatestructure 382.

FIGS. 10 and 11D depict the roof stiffener 222 adhered or bonded to theroof bow 190 via the adhesive 156. The roof stiffener 222 can begenerally U-shaped with mounting flanges 390, 392 fixedly attached(e.g., welded) to the lower surface of the roof panel 200. An endportion 396 of the flange 390 is offset from the lower surface of theroof panel 200. The roof bow 190 includes an outer panel 400 and aninner panel 402 that is fixedly attached (e.g., welded) to the outerpanel. With the shape of the end portion 396, a continuous verticalspacing between the end portion 396 of the roof stiffener 222 and theouter panel 400 of the roof bow 190 is approximately 4 mm toapproximately 6 mm, which allows for the application of the adhesive 156between the end portion 396 and the outer panel 400. An end portion 410of the roof stiffener 222 includes a locking member, such as a weld nutor swage nut 416, secured thereto. The end portion 410 is fastened tothe roof bow 190 via a fastener (e.g., a bolt) inserted through anopening in a mounting tab 420 located on the outer panel 400 andthreadingly engaging the weld nut 416.

Accordingly, the present disclosure provided a method of securing a roofcomponent 140 formed of aluminum or aluminum-based alloy to a vehiclebody component 124 formed of a steel or steel-based alloy. The exemplarymethod generally comprises providing the roof component 140 including aperipheral flange structure 150 that defines a roof adhesive bondingzone 160; providing the vehicle body component 124 including an opening,the vehicle body component 124 includes a body adhesive bonding zone 162which surrounds the opening; removably fastening the roof component 140to the vehicle body component 124 with the peripheral flange structure150 spaced from the vehicle body component; electrocoating the roofcomponent 140 secured to the vehicle body component 124 including theroof adhesive bonding zone 160 and the body adhesive bonding zone 162;painting the roof component 140 secured to the vehicle body component124; removing the painted roof component 140 from the painted vehiclebody component 124; applying an adhesive 156 that is curable at roomtemperature to at least one of the roof adhesive bonding zone 160 andthe body adhesive bonding zone 162; securely fastening the painted roofcomponent 140 to the painted vehicle body component 124 with theadhesive 156 spanning the adhesive bonding zones 160, 162; and curingthe adhesive 156.

The exemplary method further includes providing at least one supportbracket 230, 232, 234, 236 formed on an aluminum or aluminum-based alloyon the roof component 140, the at least one bracket fixedly attached(e.g., welded) to the roof component 140 and fastened to the vehiclebody component 124. As described above, the at least one bracket isconfigured to vertically space the flange structure 150 of the roofcomponent 140 from the vehicle body component 124, and according to oneaspect, the at least one bracket provides a continuous vertical spacingbetween the flange structure 150 of the roof component 140 and thevehicle body component 124 of approximately 4 mm to approximately 6 mm.

The exemplary method further includes positioning the fastenedconnection of the roof component and the vehicle body component inwardlyof the adhesive 156. As depicted in the figures, the adhesive 156provided in the spacing is outwardly of the fastened connection of theroof component 140 and the vehicle body component 124 and seals thefastened connection from moisture to prevent galvanic corrosion betweenthe dissimilar materials of the roof component 140 and the vehicle bodycomponent 124. Further, the roof component 140 is releasably fastened tothe vehicle body component 124 for electrocoating and painting in aninstallation position, and the roof component 140 is securely fastenedto the vehicle body component 124 after application of the adhesive 156in the same installation position. According to the present method, theroof component 140 and vehicle body component 124 are painted withoutmasking the electrocoated roof adhesive bonding zone 160 and theelectrocoated body adhesive bonding zone 162. Because there is nomasking, the adhesive 156 is a high modulus urethane adhesive that canadhere to paint oversprayed on the adhesive bonding zones 160, 162.

It will be appreciated that various of the above-disclosed and otherfeatures and functions, or alternatives or varieties thereof, may bedesirably combined into many other different systems or applications.Also that various presently unforeseen or unanticipated alternatives,modifications, variations or improvements therein may be subsequentlymade by those skilled in the art which are also intended to beencompassed by the following claims.

The invention claimed is:
 1. A method of securing a roof componentformed of aluminum or aluminum-based alloy to a vehicle body componentformed of a steel or steel-based alloy, the method comprising: providingthe roof component including a peripheral flange structure that definesa roof adhesive bonding zone; providing the vehicle body component, thevehicle body component includes a body adhesive bonding zone; removablyfastening the roof component to the vehicle body component with theperipheral flange structure spaced from the vehicle body component;electrocoating the roof component secured to the vehicle body componentincluding the roof adhesive bonding zone and the body adhesive bondingzone; painting the roof component secured to the vehicle body component;removing the painted roof component from the painted vehicle bodycomponent; applying an adhesive that is curable at room temperature toat least one of the roof adhesive bonding zone and the body adhesivebonding zone; securely fastening the painted roof component to thepainted vehicle body component with the adhesive spanning the adhesivebonding zones; and curing the adhesive.
 2. The method of claim 1,further including providing at least one bracket on the roof component,the at least one bracket fixedly attached to the roof component andfastened to the vehicle body component.
 3. The method of claim 2,wherein the at least one bracket is configured to vertically space theflange structure of the roof component from the vehicle body component.4. The method of claim 3, wherein the at least one bracket provides acontinuous vertical spacing between the flange structure of the roofcomponent and the vehicle body component of approximately 4 mm toapproximately 6 mm.
 5. The method of claim 3, wherein the adhesiveprovided in the spacing is outwardly of the fastened connection of theroof component and the vehicle body component and seals the fastenedconnection from moisture to prevent galvanic corrosion between thedissimilar materials of the roof component and the vehicle bodycomponent.
 6. The method of claim 1, wherein the roof component isreleasably fastened to the vehicle body component for electrocoating andpainting in an installation position, and the roof component is securelyfastened to the vehicle body component after application of the adhesivein the same installation position.
 7. The method of claim 1, furtherincluding positioning the fastened connection of the roof component andthe vehicle body component inwardly of the adhesive.
 8. The method ofclaim 1, wherein the roof component and vehicle body component arepainted without masking the electrocoated roof adhesive bonding zone andthe electrocoated body adhesive bonding zone.
 9. The method of claim 8,wherein the adhesive is a high modulus urethane adhesive that can adhereto paint oversprayed on the adhesive bonding zones.
 10. A method ofsecuring a roof component formed of aluminum or aluminum-based alloy toa vehicle body component formed of a steel or steel-based alloy, themethod comprising: providing the roof component that includes a roofadhesive bonding zone; providing the vehicle body component thatincludes a body adhesive bonding zone; positioning the roof adhesivebonding zone opposite the body adhesive bonding zone to define a spacingtherebetween having a predetermined distance; removably fastening theroof component to the vehicle body component, the fastened connection isinwardly of the roof and body adhesive bonding zones; electrocoating theroof component secured to the vehicle body component including the roofadhesive bonding zone and the body adhesive bonding zone; painting theroof component secured to the vehicle body component without masking thee-coated adhesive bonding zones; removing the painted roof componentfrom the painted vehicle body component; applying an adhesive to atleast one of the roof adhesive bonding zone and the body adhesivebonding zone; securely fastening the painted roof component to thepainted vehicle body component with the adhesive positioned in thespacing to bond the roof adhesive bonding zone to the body adhesivebonding zone; and curing the adhesive.
 11. The method of claim 10,further including providing at least one bracket on the roof component,the at least one bracket fixedly attached to the roof component andhaving a fastening member to be fastened to the vehicle body component.12. The method of claim 11, wherein the fastening member is positionedinwardly of the roof adhesive bonding zone.
 13. The method of claim 11,wherein the at least one bracket is configured to vertically space theroof adhesive bonding zone from the body adhesive bonding zone.
 14. Themethod of claim 10, wherein the roof component is releasably fastened tothe vehicle body component for electrocoating and painting in aninstallation position, and the roof component is securely fastened tothe vehicle body component after application of the adhesive in the sameinstallation position.
 15. The method of claim 10, wherein the adhesiveis a high modulus urethane adhesive that can adhere to paint oversprayedon the adhesive bonding zones.